Determining Best Calorimeter
Background: Calorimetry is the science of measuring the heat of chemical reactions or physical changes. Calorimetry is performed with a calorimeter. A calorimeter can be any container from a cup to a Calorimeters need to be well insulated as calorimetry relies on the fact that temperature change only occurs within the solution and that no heat escapes to the surroundings. That is why it is important that calorimeters are well insulated. However, heat loss cannot be avoided so scientists, when conducting experiments, need to choose the calorimeter that allows least heat energy to escape, therefore, retaining as much heat within the solution Research Question: By measuring temperature change of the reaction between hydrochloric acid (1.0M) and sodium hydroxide (1.0M) in different calorimeters, is a glass, styrofoam or copper calorimeter best for this reaction? Aim: By adding 40cm3 of 1.0M of hydrochloric acid (HCl) to 40cm3 of 1.0M of sodium hydroxide (NaCl) of known temperature in different calorimeters (glass, styrofoam or copper), this experiment will measure temperature change of the solution with time and hence deduce which calorimeter is best Hypothesis: The best form of calorimeter is one in which least heat energy is lost to the surroundings; i.e., the one in which the heat energy of the solution is retained best. One way of measuring heat energy is by measuring temperature of a solution using a thermometer. So, the best calorimeter would be the one where the temperature change is the greatest as most heat energy is kept with the solution. According to this idea, the calorimeter, which is most insulated or is made of a good insulator, will prevent heat from escaping from the solution and hence that would be the best calorimeter. From my list of calorimeters, which I will be testing (glass, styrofoam or copper), I predict that the styrofoam calorimeter will be the best insulator while copper will be the worst. This is because styrofoam is an insulator while copper is a conductor and so heat will be lost. Glass, I predict, will be in between styrofoam and copper as it’s a weaker insulator compared to styrofoam. Variables:
* Material of calorimeter: The experiment will be conducted with each material of calorimeter (glass/copper/styrofoam) and the person conducting the experiment will change this * Time: The time will be started with a stopwatch and temperature change will be measured according to it so that a graph can be plotted Dependent:
* Temperature change: Depending on the material the calorimeter is made of, the temperature will change differently as more heat can be lost in certain materials compared to others Controlled:
* Volumes of HCl and NaOH: 40cm3 of HCl is being added to 40cm3 of NaOH each trial for every type of calorimeter * Temperature of room: The room must be at a consistent temperature so as to not affect the temperature of the reacting solutions * Same concentration of HCl and NaOH: Both concentrations of NaOH and HCl are kept at 1.0M throughout the experiment for all trials, as different concentrations will mean different amounts are reacting so temperature change would be different.
* 500ml of Sodium Hydroxide (NaOH) (1.0M)
* 500ml of Hydrochloric Acid (HCl) (1.0M)
* 2 disposable pipettes
* 2 measuring cylinders
* 1 Glass beaker (Calorimeter #1)
* 1 Styrofoam cup (Calorimeter #2)
* 1 Copper cup (Calorimeter #3)
* 1 Thermometer
* Lid for calorimeters (wooden with hole so that the thermometer can pass through) * Stopwatch
* Wear safety goggles at all times in the lab to protect eyes from any acid or alkali splashing into them * Hydrochloric acid is extremely corrosive; if it comes into contact with skin or any part of the body, wash the affected area immediately and thoroughly with soap and water *...